Motor assembly

ABSTRACT

A motor assembly includes a motor including a rotor that rotates about a motor axis, a transmission that transmits motive power of the motor to an axle, a housing that accommodates the motor and the transmission, and an oil pump fixed to the housing. The housing includes a tubular motor housing extending along the motor axis, and the motor housing includes a rib on a side surface facing the oil pump. The rib protrudes to a radially outer side from the side surface, and has a plate shape extending along the motor axis.

CROSS REFERENCE TO RELATED APPLICATION

The present invention claims priority under 35 U.S.C. § 119 to JapaneseApplication No. 2018-198507 filed on Oct. 22, 2018 and JapaneseApplication No. 2019-001240 filed on Jan. 8, 2019, the entire contentsof which are hereby incorporated herein by reference.

1. FIELD OF THE INVENTION

The present disclosure relates to a motor unit.

2. BACKGROUND

Conventionally, various countermeasures against the motor vibration havebeen known. For example, there are known a method for reducing anexcitation force that excites vibration and a method for reducingvibration at a motor attachment portion.

A motor unit used as a vehicle driving device as in the present exampleembodiment is configured by combining a motor, a gear, an electric oilpump, and the like. In such a motor unit, the motor unit vibrates due toarrangement and weight balance of components, and thus, there is a casewhere the vibration is insufficiently reduced with the conventionalvibration countermeasures.

SUMMARY

According to one example embodiment of the present disclosure, a motorassembly includes a motor including a rotor that rotates about a motoraxis, a transmission that transmits motive power of the motor to anaxle, a housing that accommodates the motor and the transmission, and anoil pump fixed to the housing. The housing includes a tubular motorhousing extending along the motor axis, and the motor housing includes arib on a side surface facing the oil pump, the rib protruding to aradially outer side from the side surface.

The above and other elements, features, steps, characteristics andadvantages of the present disclosure will become more apparent from thefollowing detailed description of the example embodiments with referenceto the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a motor assembly according to an exampleembodiment of the present disclosure as viewed from above.

FIG. 2 is a perspective view of a motor assembly according to an exampleembodiment of the present disclosure as viewed from below.

FIG. 3 is a side view of a motor assembly according to an exampleembodiment of the present disclosure.

FIG. 4 is a perspective view illustrating a state where a side connectorcover of a motor assembly according to an example embodiment of thepresent disclosure has been detached.

FIG. 5 is a perspective view illustrating a state where a lowerconnector cover of a motor assembly according to an example embodimentof the present disclosure has been detached.

FIG. 6 is a side view illustrating the side connector cover and an axleconnection portion.

FIG. 7 is a perspective view illustrating a state where an inverter hasbeen detached.

FIG. 8 is a longitudinal cross-sectional view illustrating a motorportion of a motor assembly according to an example embodiment of thepresent disclosure.

DETAILED DESCRIPTION

In the following description, a description will be given by defining avertical direction based on a positional relationship when a motorassembly 1 according to an example embodiment of the disclosureillustrated in FIG. 1 is mounted on a vehicle located on a horizontalroad surface. In the accompanying drawings, an XYZ coordinate system isillustrated appropriately as a three-dimensional orthogonal coordinatesystem. In the XYZ coordinate system, a Z-axis direction is the verticaldirection in which a +Z side is an upper side and a −Z side is a lowerside. An X-axis direction is a direction orthogonal to the Z-axisdirection and is a front-rear direction of the vehicle on which themotor assembly 1 is mounted. In the present example embodiment, a +Xside is a front side of the vehicle, and a −X side is a rear side of thevehicle. A Y-axis direction is a direction orthogonal to both the X-axisdirection and the Z-axis direction, and is a left-right direction of thevehicle. In the present example embodiment, a +Y side is a left side ofthe vehicle, and a −Y side is a right side of the vehicle. In thepresent example embodiment, the right side corresponds to one side in anaxial direction, and the left side corresponds to the other side in theaxial direction. In addition, the front-rear direction corresponds to apredetermined direction in the present example embodiment.

Incidentally, the positional relationship in the front-rear direction isnot limited to the positional relationship in the present exampleembodiment, and the +X side may be the rear side of the vehicle, and the−X side may be the front side of the vehicle. In this case, the +Y sideis the right side of the vehicle, and the −Y side is the left side ofthe vehicle.

A motor axis J1 illustrated as appropriate in the drawings extends inthe Y-axis direction, that is, the left-right direction of the vehicle.In the following description, a direction parallel to the motor axis J1is simply referred to as the “axial direction”, a radial directionhaving its center on the motor axis J1 is simply referred to as the“radial direction”, and a circumferential direction having its center onthe motor axis J1, that is, the axial circumference of the motor axisJ1, is simply referred to as the “circumferential direction” unlessotherwise noted. In the present specification, the “parallel direction”also includes a substantially parallel direction, and the “orthogonaldirection” also includes a substantially orthogonal direction.

The motor assembly 1 is mounted on a vehicle using a motor as a motivepower source, such as a hybrid electric vehicle (HEV), a plug-in hybridvehicle (PHV), and an electric vehicle (EV), and is used as the motivepower source. As illustrated in FIGS. 1 to 4, the motor assembly 1includes a housing 10, a motor 20, and an inverter 40. Although notillustrated, the motor assembly 1 includes a speed reducer and adifferential device.

The housing 10 houses the motor 20, the speed reducer (not illustrated),and the differential device (not illustrated). Although not illustrated,oil is accommodated in the housing 10. As illustrated in FIGS. 1 to 3,the housing 10 includes a housing body 11, a gear cover 12, and a motorcover 13.

As illustrated in FIG. 2, the housing body 11 includes a motor housing11 a and a coupling portion 11 b. The motor housing 11 a has a tubularshape surrounding the motor axis J1 and extending in the axialdirection. The motor housing 11 a is open to the right side, which isthe −Y side illustrated in the drawings. The motor housing 11 a housesthe motor 20. The coupling portion 11 b is provided at a left endportion of the motor housing 11 a. The coupling portion 11 b protrudesto the rear side of the motor housing 11 a.

The housing body 11 has a plurality of ribs 11A on a surface of thetubular motor housing 11 a. The plurality of ribs 11A include a ribextending in the circumferential direction at a radial end portion ofthe motor housing 11 a and a rib extending in the axial direction. Sincethe plurality of ribs 11A are provided, the rigidity of the housing body11 is improved, and it is possible to reduce noise caused by vibrationof the housing body 11 when the motor 20 is driven.

The gear cover 12 is fixed to the left side of the housing body 11. Morespecifically, a right end portion of the gear cover 12 is fixed to thecoupling portion 11 b with a screw. The gear cover 12 is open to theright side although not illustrated. The gear cover 12 includes a firstaccommodating portion 12 a and a second accommodating portion 12 b. Thefirst accommodating portion 12 a is located on the left side of themotor housing 11 a. The first accommodating portion 12 a accommodatesthe speed reducer (not illustrated). The second accommodating portion 12b is connected to the rear side of the first accommodating portion 12 a.The second accommodating portion 12 b is located on the left side of theportion of the coupling portion 11 b that protrudes to the rear side ofthe motor housing 11 a. The second accommodating portion 12 baccommodates the differential device (not illustrated). The firstaccommodating portion 12 a protrudes to the left side of the secondaccommodating portion 12 b. That is, the motor assembly 1 includes thespeed reducer and the differential device serving as transmissionmechanisms that transmit motive power of the motor 20 to an axle. Thegear cover 12 constitutes a gear housing 15, which accommodates thespeed reducer and the differential device serving as the transmissionmechanisms, together with the coupling portion 11 b of the housing body11.

The motor cover 13 is fixed to the right side of the housing body 11.More specifically, the motor cover 13 is fixed to a right end portion ofthe motor housing 11 a with a screw. As illustrated in FIG. 1, the motorcover 13 closes the opening on the right side of the motor housing 11 a.

As illustrated in FIG. 8, the motor 20 includes a rotor 21 and a stator22. The rotor 21 of the motor 20 rotates about the motor axis J1. Therotor 21 of the motor 20 is connected to the speed reducer (notillustrated) accommodated in the gear cover 12. The rotation of themotor 20 is decelerated by the speed reducer (not illustrated) andtransmitted to the differential device (not illustrated). Thedifferential device transmits a torque output from the motor 20 to theaxle of the vehicle. The differential device has a ring gear thatrotates about a differential axis J2 parallel to the motor axis J1. Thetorque output from the motor 20 is transmitted to the ring gear via thespeed reducer.

As illustrated in FIG. 2, the housing 10 has an axle connection portion11 c at the coupling portion 11 b. The axle connection portion 11 c hasa tubular shape that protrudes to the vehicle right side from a surfaceof the coupling portion 11 b facing the vehicle right side (−Y side).The axle connection portion 11 c has a circular opening having itscenter on the differential axis J2. The axle of the vehicle is insertedinto the opening of the axle connection portion 11 c and connected tothe ring gear of the differential device. The vehicle axle is axiallyrotated about the differential axis J2.

As illustrated in FIGS. 1 and 2, the motor assembly 1 includes an oilpump 30, an oil cooler 35, and an electric actuator 36 as auxiliarydevices. The oil pump 30 and the oil cooler 35 are disposed in the lowerportion of the housing 10. The oil cooler 35 is located at a lower frontend portion of the motor assembly 1. The oil pump 30 is located on therear side of the oil cooler 35. The electric actuator 36 is disposed ina front portion of the housing 10. The electric actuator 36 is a drivingdevice for a parking lock mechanism.

The oil pump 30 is disposed along the motor axis J1. As illustrated inFIG. 5, the oil pump 30 includes a connector 31 and a heat sink 32 in aright end portion. The heat sink 32 is provided on a cover member of theoil pump 30. The heat sink 32 cools a circuit board built in the oilpump 30.

As illustrated in FIGS. 1 and 2, the inverter 40 is located on the rearside of the housing 10. The inverter 40 has an inverter case 41. Aninverter (not illustrated) is accommodated in the inverter case 41. Theinverter in the inverter case 41 is electrically connected to the statorof the motor 20 and drives the motor 20.

The inverter case 41 is fixed to the housing 10. That is, the invertercase 41 is provided integrally with the housing. In the present exampleembodiment, the inverter case 41 is fixed to a radially outer surface ofthe housing 10. More specifically, the inverter case 41 is fixed to arear portion of the radially outer surface of the motor housing 11 a.That is, the inverter case 41 is fixed to the rear side of the housing10 in the front-rear direction orthogonal to the axial direction.

As illustrated in FIG. 1, the inverter case 41 has a substantiallyrectangular box shape extending in the axial direction. The invertercase 41 has an inverter case body 42 and an inverter cover 43. Theinverter case body 42 has a substantially rectangular box shape that isopen on the upper side and is long in the axial direction.

The inverter cover 43 closes the opening on the upper side of theinverter case body 42. The inverter cover 43 includes a first cover 43 aand a second cover 43 b. The first cover 43 a and the second cover 43 bare separate members. In the inverter case 41, the inverter (notillustrated) is accommodated in a portion where the first cover 43 a isattached. In the inverter case 41, a bus bar (not illustrated) connectedto the inverter is accommodated in a portion where the second cover 43 bis attached.

As illustrated in FIGS. 1 to 3, a wire harness 60 and a cooling waterhose 70 are routed on a side surface of the motor assembly 1 on theright side, that is, the −Y side. Specifically, the wire harness 60 andthe cooling water hose 70 extend downward from a right side surface ofthe inverter case 41 along a lower end portion of the motor cover 13 andwrap around to the lower side of the housing 10.

As illustrated in FIGS. 1 to 3, the motor assembly 1 has a sideconnector cover 81 at ends, close to the inverter case 41, of the wireharness 60 and the cooling water hose 70. The motor assembly 1 also hasa lower connector cover 82 at ends, close to the lower portion of thehousing body 11, of the wire harness 60 and the cooling water hose 70.That is, the wire harness 60 and the cooling water hose 70 extendbetween the side connector cover 81 and the lower connector cover 82 inthe motor assembly 1.

As illustrated in FIGS. 4 and 5, the wire harness 60 includes: a firstconnector 61 connected to a connector 44 of the inverter case 41; asecond connector 62 connected to a connector 31 of the oil pump 30located in the lower portion of the housing 10; and an electric wire 63connecting the first connector 61 and the second connector 62.

As illustrated in FIG. 4, the inverter case 41 has the connector 44 at acorner on the front side of a right side surface of the inverter casebody 42. The connector 44 protrudes obliquely forward from the corner ofthe inverter case body 42. The connector 44 is located in a gap betweenthe inverter case 41 and the housing body 11 in the front-reardirection. The first connector 61 of the wire harness 60 is connected tothe connector 44.

In the inverter case 41, the connector 14 protruding from a surfacefacing the rear side of the housing body 11 is disposed on the lowerside of the connector 44. The connector 14 of the housing body 11 isconnected to a partial terminal of the connector 44. Although notillustrated, an electric wire connected to the connector 14 includes anelectric wire connected to the first connector 61 and a connectorconnected to the connector 14. The connector 14 of the housing body 11protrudes obliquely to the rear right side from a back surface of thehousing body 11. That is, a protruding direction of the connector 14 isa direction that intersects a protruding direction of the connector 44of the inverter case 41. In the present example embodiment, theprotruding direction of the connector 14 and the protruding direction ofthe connector 44 are substantially orthogonal as viewed from above.

As illustrated in FIG. 5, the oil pump 30 and the oil cooler 35 aredisposed in the lower portion of the housing 10. The oil pump 30 has theconnector 31 for power supply and signal input. The second connector 62of the wire harness 60 is connected to the connector 31 of the oil pump30.

As illustrated in FIGS. 4 and 5, the cooling water hose 70 is connectedto a hose nipple 71 protruding from the right side surface of theinverter case 41 and to a hose nipple 72 located in the lower portion ofthe housing 10.

The inverter case 41 has the two hose nipples 71 and 73 at a lowerportion of the right side surface of the inverter case body 42. The hosenipple 73 located on the rear side between the hose nipples 71 and 73 isa cooling water supply port to the inverter case 41. The cooling waterhose (not illustrated) is connected to the hose nipple 73. The hosenipple 71 located on the front side between the hose nipples 71 and 73is a cooling water discharge port from the inverter case 41.

The hose nipple 72 in the lower portion of the housing 10 is a coolingwater supply port to the oil cooler 35 attached to the housing body 11.Although not illustrated, the housing 10 has a hose nipple as a coolingwater discharge port from the oil cooler 35. A lower end portion of thecooling water hose 70 is connected to the hose nipple 72.

The hose nipple 72 and the connector 31 of the oil pump 30 are disposedat positions close to each other in the lower portion of the housing 10.Specifically, the oil cooler 35 and the oil pump 30 are disposed side byside. The hose nipple 72 connected to the oil cooler 35 is located at arear end portion of the oil cooler 35. The connector 31 of the oil pump30 is located at a front end portion of the oil pump 30.

The side connector cover 81 covers the connector 44 of the inverter case41 and the first connector 61 of the wire harness 60, the connector 14of the housing 10, and a part of the cooling water hose 70 from thelateral side as illustrated in FIG. 3.

Therefore, the motor assembly 1 of the present example embodimentincludes the side connector cover 81, which covers the first connector61 from the lateral side, on the right side surfaces of the invertercase 41 and the housing 10. According to this configuration, even whenan impact is applied from a side surface of the vehicle, it is difficultfor the wire harness 60 to be disconnected even in the event of acollision since the first connector 61 is protected by the sideconnector cover 81.

In addition, since the side connector cover 81 also covers the connector14 of the housing 10 from the lateral side in the present exampleembodiment, the wire harness connecting the connector 44 and theconnector 14 is also protected by the side connector cover 81.

As illustrated in FIGS. 2 and 3, the side connector cover 81 includes abottom wall 81 a facing the lower side, a rear opening 81 b that is opento the rear side of the bottom wall 81 a, and a front opening 81 c thatis open to the front side of the bottom wall 81 a. As illustrated inFIG. 3, the bottom wall 81 a is located on the upper side of the axleconnection portion 11 c. The connector 14, the connector 44, and thefirst connector 61 illustrated in FIG. 4 are disposed on the upper sideof the bottom wall 81 a. As viewed from the axle connected to the axleconnection portion 11 c, the bottom wall 81 a covers the connector 14,the connector 44, and the first connector 61.

That is, the motor assembly 1 of the present example embodiment has aconfiguration in which the housing 10 has the axle connection portion 11c to which the axle of the vehicle is connected, the connector 44 of theinverter case 41 is located on the radially outer side of the axleconnected to the axle connection portion 11 c, and the side connectorcover 81 covers the first connector 61 as viewed from the axle.

According to this configuration, even when a flying stone hits the axlethat rotates in the lower portion of the motor assembly 1 and jumpsupward or a liquid adhering to the axle is scattered, the firstconnector 61 is protected by the bottom wall 81 a of the side connectorcover 81. Therefore, the connector can be effectively protected from theflying stone or the like during travel of the vehicle.

As illustrated in FIGS. 2 and 6, a lower surface of the bottom wall 81 ais a curved surface which is convex upward and extends along thecurvature of the axle connected to the axle connection portion 11 c.Since the lower surface of the bottom wall 81 a is the curved surface, aforeign matter such as a flying stone after being bounced off by at theaxle can be bounced back to the road surface side by the lower surfaceof the bottom wall 81 a. As a result, it is possible to prevent theforeign matter bounced back by the side connector cover 81 from hittingor adhering to the other parts of the motor assembly 1.

In addition, the axle has a boot (not illustrated), and the boot islarger in the radial direction than the axle. Since the bottom wall 81 ais provided, when climbing a step or the like at high-speed rotation, itis possible to prevent the axle from being deflected and the boot fromcoming into contact with the connector and the like.

In the present example embodiment, the side connector cover 81 holds apart of the cooling water hose 70 between the side connector cover 81and the inverter case 41 as illustrated in FIG. 3. The cooling waterhose 70 is connected to the hose nipple 71 at the rear opening 81 b inthe rear end portion of the side connector cover 81. A front portion ofthe cooling water hose 70 extends to the front lower side from the frontopening 81 c of the side connector cover 81.

According to this configuration, the cooling water hose 70 is held atthe position that does not protrude to the right side of the motorassembly 1, and thus, it is possible to reduce an axial length of themotor assembly 1. In addition, the cooling water hose 70 is less likelyto hinder when the motor assembly 1 is mounted on the vehicle, and thus,workability is improved. According to the above configuration, it ispossible to suppress contact between the cooling water hose 70 and avehicle frame or the like, and thus, it is possible to suppressunintentional wear or breakage of the cooling water hose 70.

The side connector cover 81 is disposed to straddle the inverter case 41and the housing 10 as viewed from the lateral side, and is fixed to boththe inverter case 41 and the housing 10. Specifically, the sideconnector cover 81 is fixed to the inverter case 41 with a bolt 91 andfixed to the motor cover 13 of the housing 10 with two bolts 92 and 93as illustrated in FIG. 3.

According to this configuration, the side connector cover 81 can morereliably protect both the connector 44 of the inverter case 41 and theconnector 14 of the housing 10. If the side connector cover 81 is fixedonly to the inverter case 41, the side connector cover 81 correspondingto the portion that covers the connector 14 of the housing 10 is notfixed, and thus, sound is generated due to vibration, and a flying stoneor water easily enters through a gap between the housing 10 and the sideconnector cover 81. Therefore, the connector protection using the sideconnector cover 81 becomes more reliable according to the configurationof the present example embodiment.

The side connector cover 81 covers the connector 44 of the inverter case41 and the first connector 61 of the wire harness 60, the connector 14of the housing 10, and a part of the cooling water hose 70 from thelateral side as illustrated in FIG. 3.

Therefore, the motor assembly 1 of the present example embodimentincludes the side connector cover 81, which covers the first connector61 from the lateral side, on the right side surfaces of the invertercase 41 and the housing 10. According to this configuration, even whenan impact is applied from a side surface of the vehicle, it is difficultfor the wire harness 60 to be disconnected even in the event of acollision since the first connector 61 is protected by the sideconnector cover 81.

The lower connector cover 82 covers the connector 31 of the oil pump 30,the second connector 62 of the wire harness 60 connected to theconnector 31, and the hose nipple 72 of the housing 10 from the lowerside, in the lower portion of the housing 10 as illustrated in FIGS. 2and 5. As illustrated in FIGS. 2 and 3, the lower connector cover 82 hasan opening 82 a that is open to the right. The wire harness 60 and thecooling water hose 70 are inserted into the lower connector cover 82through the opening 82 a. The lower connector cover 82 is fixed to thelower surface of the housing body 11 by a plurality of bolts includingthe bolt 93 illustrated in FIG. 2.

Therefore, the motor assembly 1 of the present example embodimentincludes the lower connector cover 82 that covers the second connector62 from the lower side in the lower portion of the housing 10. Accordingto this configuration, the second connector 62 is protected from aflying stone, road surface water, and the like in the lower portion ofthe motor assembly 1 exposed on the lower surface of the vehicle, andthus, the wire harness 60 is unlikely to be disconnected in theconnector and in the periphery thereof.

In addition, the second connector 62 of the wire harness 60 is protectedby the lower connector cover 82 even when the electronic component suchas the oil pump 30 is disposed in the lower portion of the motorassembly 1 according to the motor assembly 1 of the present exampleembodiment. That is, the connector and the periphery thereof, which arelikely to be disconnected, can be disposed in the lower portion of themotor assembly 1 according to the motor assembly 1 of the presentexample embodiment. Therefore, restrictions on the arrangement of theelectronic components in the motor assembly 1 are reduced according tothe present example embodiment.

In addition, the motor assembly 1 of the present example embodimentincludes the cooling water hose 70 connected to the hose nipple 71 ofthe inverter case 41 and to the hose nipple 72 of the housing 10, andthe lower connector cover 82 is configured to cover the second connector62 and the hose nipple 72 of the housing 10 from the lower side.According to this configuration, connecting portions of the coolingwater hose 70 are also protected from a flying stone.

Since the connector 31 of the oil pump 30 and the hose nipple 72 aredisposed close to each other in the present example embodiment, thelower connector cover 82 covering the connector 31 and the hose nipple72 can be made small. As a result, it is possible to configure the lowerportion of the motor assembly 1 such that only a portion that needs tobe protected from a flying stone is covered by the lower connector cover82 and a portion that needs to be cooled, for example, is not covered bythe lower connector cover 82.

Specifically, the motor assembly 1 of the present example embodiment hasthe configuration in which the oil pump 30 has the heat sink 32 thatcools the internal components of the oil pump 30, and the heat sink 32is located outside the lower connector cover 82. According to thisconfiguration, the heat sink 32 is exposed in the lower portion of themotor assembly 1, and thus, the heat sink 32 and the internal componentsof the oil pump 30 are efficiently cooled during travel of the vehicle.

FIG. 7 is a perspective view of the motor assembly 1 according to theexample embodiment from which the inverter 40 has been detached asviewed from the rear side. FIG. 8 is a longitudinal cross-sectional viewillustrating a motor portion of the motor assembly 1 according to theexample embodiment.

In the motor assembly 1 of the present example embodiment, the housing10 has a pump housing 17 provided on an outer circumferential surface ofthe motor housing 11 a as illustrated in FIG. 7. The pump housing 17 hasa tubular shape that is open on both sides in the Y-axis direction. Anopening of the pump housing 17 facing the vehicle left side (+Y side) isopen inside the gear housing 15. The oil pump 30 is inserted into anopening of the pump housing 17 facing the vehicle right side (−Y side).In the present example embodiment, the oil pump 30 is an electric oilpump. The oil pump 30 is fixed to the opening on the right side of thepump housing 17 by bolt fastening. The oil pump 30 circulates oil insidethe housing 10.

In the motor assembly 1, the heavy oil pump 30 is disposed in the lowerportion of the motor housing 11 a. In this configuration, when the oilpump 30 vibrates in the radial direction of the motor housing 11 a, themotor housing 11 a itself connected to the pump housing 17 may deformand vibrate, which causes noise in some cases.

A motor assembly used as a vehicle driving device as in the presentexample embodiment is configured by combining a motor, a gear, anelectric oil pump, and the like. In such a motor assembly, the motorassembly vibrates due to arrangement and weight balance of components,and thus, there is a case where the vibration is insufficiently reducedwith the conventional vibration countermeasures.

Therefore, in the motor assembly 1 of the present example embodiment, arib 111 extending along the direction of the motor axis J1 and a rib 112orthogonal to the rib 111 are provided at a lower portion of a sidesurface facing the rear side of the motor housing 11 a as illustrated inFIGS. 7 and 8. The rib 112 extends along the circumferential directionaround the motor axis J1.

The motor housing 11 a includes a plurality of radial protrusions 121,122, 123, and 124 that protrude to the radially outer side from the sidesurface of the motor housing 11 a. Both ends of the rib 111 areconnected to the radial protrusions 121 and 122. Both ends of the rib112 are connected to the radial protrusions 123 and 124.

The radial protrusion 121 is a boss coupler having a rectangular frameshape in a plan view. The radial protrusion 121 has four bosses 121 aand four plate-shaped coupling ribs 121 b. The coupling rib 121 bcouples the two bosses 121 a adjacent in the axial direction or thecircumferential direction. The end on the vehicle right side (−Y side)of the rib 111 is connected to a side surface facing the vehicle leftside (+Y side) of the coupling rib 121 b located at an end on thevehicle left side (+Y side) of the radial protrusion 121.

The radial protrusion 122 is a casing portion that extends in the radialdirection from the side surface of the motor housing 11 a and is coupledto a side surface of the axle connection portion 11 c. The radialprotrusion 122 has a side surface facing the vehicle right side (−Yside) between the motor housing 11 a and the axle connection portion 11c. The end on the vehicle left side (+Y side) of the rib 111 isconnected to the side surface facing the vehicle right side (−Y side) ofthe radial protrusion 122.

The radial protrusion 123 is a connector that connects the motor 20 andthe inverter 40. The radial protrusion 123 protrudes to the rear side(−X side) from the side surface of the motor housing 11 a. The upper endof the rib 112 is connected to a side surface facing the lower side ofthe radial protrusion 123.

The radial protrusion 124 is a rib that protrudes to the radially outerside from the lower portion of the motor housing 11 a. The lower end ofthe rib 112 is connected to the side surface facing the rear side (−Xside) of the radial protrusion 124.

The rib 111 extends along the motor axis J1 between the radialprotrusions 121 and 122. The rib 112 extends along the circumferentialdirection between the radial protrusions 123 and 124. The rib 111 andthe rib 112 intersect each other at the center of a region surrounded bythe four radial protrusions 121 to 124. In the present exampleembodiment, the rib 111 and the rib 112 are substantially orthogonal asviewed in the front-rear direction (X-axis direction).

As illustrated in FIGS. 7 and 8, the oil pump 30 is located on theradially outer side of the motor housing 11 a. More specifically, asillustrated in FIG. 8, the oil pump 30 is located slightly on the rearside of the lower portion of the motor housing 11 a as viewed in thedirection along the motor axis J1. The ribs 111 and 112 are located inthe lower portion of the side surface facing the rear side of the motorhousing 11 a. That is, the motor housing 11 a has the rib 111 and therib 112 that protrude to the radially outer side from the side surfaceof the motor housing 11 a on the side surface facing the oil pump 30side.

The positions of the ribs 111 and 112 may be deviate from theillustrated positions in the circumferential direction as long asfalling within a range located below a virtual line L1 illustrated inFIG. 8 on the side surface of the motor housing 11 a. The virtual lineL1 is a virtual line orthogonal to a virtual line L2 connecting themotor axis J1 and a motor axis J3 of the oil pump 30 in a cross sectionorthogonal to the motor axis J1 illustrated in FIG. 8.

The oil pump 30 is heavy, and thus, sometimes vibrates in a differentperiod in a direction different from that of the motor 20 during theoperation. Then, the oil pump 30 and the motor 20 move so as to approachor separate in the radial direction of the motor axis J1. When the oilpump 30 swings relative to the motor 20 in this manner, the side surfaceof the motor housing 11 a facing the oil pump 30 side is pulled orpushed by the oil pump 30, and thus, the entire motor housing 11 avibrates so as to bend.

According to the motor assembly 1 of the present example embodiment, theribs 111 and 112 are provided on the side surface of the motor housing11 a facing the oil pump 30 side, and thus, the connecting portionbetween the motor housing 11 a and the oil pump 30 and the peripheralportion thereof are made to be hardly deformed. As a result, a relativeamplitude between the oil pump 30 and the motor housing 11 a can bereduced, and the vibration of the entire motor assembly 1 can besuppressed. As a result, the noise caused by the vibration can also bereduced.

In the motor assembly 1, the oil pump 30 is disposed so as to overlapthe motor housing 11 a as viewed in the radial direction of the motoraxis J1. In such a configuration, the area where the oil pump 30 and themotor housing 11 a face each other is wider than that of a case wherethe oil pump 30 and the motor housing 11 a are disposed to be shifted inthe axial direction, and thus, the vibration of the motor housing 11 ais easily induced by the vibration of the oil pump 30. Since the ribs111 and 112 are provided in the configuration of the present exampleembodiment, it is possible to suppress the vibration of the portion thatis likely to vibrate and to obtain a strong vibration suppressing effectas a whole.

In the motor assembly 1, the housing 10 has the pump housing 17 thataccommodates the oil pump 30, and the pump housing 17 is provided on theouter circumferential surface of the motor housing 11 a. In such aconfiguration, the pump housing 17 and the motor housing 11 a areconnected, and thus, the vibration of the motor housing 11 a is moreeasily induced by the vibration of the oil pump 30. Since the ribs 111and 112 are provided in the configuration of the present exampleembodiment, it is possible to suppress the vibration of the portion thatis likely to vibrate and to obtain a strong vibration suppressing effectas a whole.

In the present example embodiment, the rib 111 has a plate shapeextending along the motor axis J1. According to this configuration, therib 111 is disposed substantially in parallel to the vibration thatcompresses or stretches the side surface of the motor housing 11 a inthe direction along the motor axis J1. Since the rib 111 is disposed ina posture that is hardly deformed with respect to the vibration, thevibration of the motor housing 11 a can be suppressed.

In the present example embodiment, the rib 112 has a plate shapeextending along the circumferential direction around the motor axis J1.When the oil pump 30 moves relative to the motor 20 in the radialdirection, the motor housing 11 a is deformed into an elliptical shapehaving the virtual lines L1 and L2 as major and minor axes,respectively, in the cross section illustrated in FIG. 8. Since the rib112 extending in the circumferential direction is provided, it ispossible to suppress the deformation of the motor housing 11 a into theelliptical shape, and to reduce the vibration of the entire motorhousing 11 a.

In addition, the rib 115 and the rib 116 are also provided on the sidesurface of the motor housing 11 a that faces the side opposite to theoil pump 30 in the motor assembly 1 of the present example embodiment.In the present example embodiment, the ribs 115 and 116 are located onthe upper surface of the motor housing 11 a. The ribs 115 and 116 have aplate shape extending along the motor axis J1. According to thisconfiguration, the upper surface portion of the motor housing 11 a canbe made to be hardly deformed. The upper surface of the motor housing 11a has a relatively wide surface that is not connected to the othermembers of the motor assembly 1, and thus, is more likely to vibratethan the other portions of the motor housing 11 a. Since the ribs 115and 116 are provided on the upper surface of the motor housing 11 a thatis likely to vibrate in this manner, the entire motor housing 11 a ishardly deformed, and thus, the vibration of the motor housing 11 a isfurther suppressed.

Incidentally, the motor housing 11 a may be configured not to includethe ribs 115 and 116 on the upper surface.

The motor assembly 1 of the present example embodiment includes the gearhousing 15 that accommodates the transmission mechanism, and the motorhousing 11 a and the pump housing 17 are fixed to a side surface of thecoupling portion 11 b constituting the gear housing 15, the side surfacefacing in the direction of the motor axis J1. When the motor housing 11a and the pump housing 17 are fixed to the side surface of the commoncoupling portion 11 b, the oil pump 30 swings in the radial direction ofthe motor housing 11 a with the connection portion between the oil pump30 and the coupling portion 11 b as a fulcrum. Thus, the amplitude ofvibration increases at the end of the oil pump 30 on the side oppositeto the gear housing 15, and the side surface of the motor housing 11 ais likely to be deformed. Since the ribs 111 and 112 are provided in theconfiguration of the present example embodiment, it is possible tosuppress the vibration of the portion that is likely to vibrate and toobtain a strong vibration suppressing effect as a whole.

As illustrated in FIG. 7, the housing 10 of the motor assembly 1 of thepresent example embodiment includes the gear housing 15 thataccommodates the transmission mechanism and the axle connection portion11 c to which the axle is connected, and the motor housing 11 a and theaxle connection portion 11 c are disposed to be adjacent to each otherin the radial direction of the motor axis J1. Further, the motorassembly 1 has a rib 114 that extends between the motor housing 11 a andthe axle connection portion 11 c in the circumferential direction.

On the upper side of the rib 114, a radial protrusion 125 protruding inthe radial direction from the side surface facing the rear side (−Xside) of the motor housing 11 a is located. In the present exampleembodiment, the radial protrusion 125 is a plate-shaped rib extendingalong the direction of the motor axis J1 on the outer circumferentialsurface of the motor housing 11 a. An end on the vehicle left side (+Yside) of the radial protrusion 125 is connected to a surface facing thevehicle right side (−Y side) of the coupling portion 11 b. An upper endof the rib 114 is connected to a lower surface of the radial protrusion125. A lower end of the rib 114 is connected to an upper surface of theaxle connection portion 11 c.

The axle connection portion 11 c is a cylindrical member, and thedifferential device that is a heavy object is disposed therein. Thus,when the axle connection portion 11 c vibrates, the motor housing 11 ais deformed similarly to the case where the oil pump 30 vibrates, whichmay cause noise in some cases. Therefore, the connecting portion betweenthe motor housing 11 a and the axle connection portion 11 c can be madeto be hardly deformed by providing the rib 114 between the motor housing11 a and the axle connection portion 11 c. As a result, the vibration ofthe motor housing 11 a can be suppressed, and the generation of noisecan be suppressed.

In addition, the rib extending between the motor housing 11 a and thegear housing 15 is provided as the radial protrusion 125 in the presentexample embodiment. As a result, the vibration of the gear housing 15with the coupling portion between the motor housing 11 a and the gearhousing 15 as a fulcrum is suppressed. Therefore, it is possible to moreeffectively suppress the vibration of the motor housing 11 a caused bythe vibration of the axle connection portion 11 c according to thepresent example embodiment. Further, in the present example embodiment,the rib 126 having the same configuration as the radial protrusion 125is provided on the upper side of the radial protrusion 125, and thus, astronger vibration suppressing effect can be obtained in the motorhousing 11 a and the gear housing 15.

Each configuration described in the present specification can beproperly combined within a range in which no conflict occurs.

Although a connection structure between the connector 44 provided in theinverter case 41 and the connector 31 of the oil pump 30 has beendescribed in the present example embodiment, an auxiliary device otherthan the oil pump 30 can be applied as a connection destination of theinverter case 41. For example, the electric actuator 36 having a parkinglock mechanism or the like may be applied as the connection destination.

Although the configuration in which the wire harness 60 and the coolingwater hose 70 extend from the side surface of the inverter case 41 tothe lower surface of the housing 10 has been described in the presentexample embodiment, the disclosure is not limited to this configuration.For example, at least one of the wire harness 60 and the cooling waterhose 70 may be configured to extend from the upper surface, the rearsurface, or the lower surface of the inverter case 41 to the lowersurface of the housing 10.

Although the configuration in which the housing 10 and the inverter case41 as separate cases are connected to be integrated has been describedin the present example embodiment, the housing 10 and the inverter case41 may each be configured as a single member. Although the configurationin which the housing 10 and the inverter case 41 as separate cases areconnected to be integrated has been described in the present exampleembodiment, the housing 10 and the inverter case 41 may each beconfigured as a single member.

While example embodiments of the present disclosure have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present disclosure. The scope of the presentdisclosure, therefore, is to be determined solely by the followingclaims.

What is claimed is:
 1. A motor assembly comprising: a motor including arotor that rotates about a motor axis; a housing that accommodates themotor; and an oil pump fixed to the housing; wherein the housingincludes a tubular motor housing extending along the motor axis; and themotor housing includes a rib on a side surface facing the oil pump, therib protruding to a radially outer side from the side surface.
 2. Themotor assembly according to claim 1, wherein the rib has a plate shapeextending along the motor axis.
 3. The motor assembly according to claim1, wherein the oil pump overlaps the motor housing as viewed in a radialdirection of the motor axis.
 4. The motor assembly according to claim 1,wherein the housing includes a pump housing that accommodates the oilpump; and the pump housing is provided on an outer circumferentialsurface of the motor housing.
 5. The motor assembly according to claim4, further comprising: a gear housing; wherein the motor housing and thepump housing are fixed to a side surface of the gear housing facing in adirection of the motor axis.
 6. The motor assembly according to claim 1,wherein the housing includes: a gear housing; and an axle connectionportion; the motor housing and the axle connection portion are adjacentto each other in a radial direction of the motor axis; and a rib extendsbetween the motor housing and the axle connection portion in acircumferential direction.